1. Field of the Invention
The invention relates to methods and apparatus for dialing an emergency telephone number from a teleworking client remotely coupled to a PBX. More particularly, the invention relates to methods and apparatus for intercepting dialed digits (e.g., TAPI messages, DTMF tones) dialed by the teleworking client, uncoupling the teleworking client from the PBX, coupling the teleworking client to the PSTN, and transmitting the digits as DTMF tones over the PSTN.
2. Brief Description of the Prior Art
People can access a wide variety of services and functions through telecommunications systems. A subscriber can receive, send, and forward voice messages, faxes, e-mail, and data, and can remotely manage many business and personal functions.
This new technology has important implications for teleworking. In teleworking, a teleworker performs work functions from a remote location. In many cases, a teleworker can perform functions identical to those performed by her colleague in the office. Teleworking can be loosely defined as workers performing work functions remotely through a telecommunications system.
Teleworking offers workers unprecedented flexibility and convenience for workers. It also provides opportunities for people who have traditionally been excluded from the work force or who have been able to participate on a limited basis only. It can remove geographical barriers, better integrate the disabled into the work force, and provide retraining and rehabilitation programs for the institutionalized.
Most advanced features are implemented and controlled through a control channel, which requires the user to have a telephone system, typically ISDN, that provides a separate channel for the control signal. Unfortunately, many subscribers do not have ISDN telephones or ISDN lines. ISDN telephones and lines are particularly rare in private homes, locations where teleworking can make the biggest difference. What is needed is a better way to integrate ordinary subscribers into teleworking.
The above referenced previously incorporated application entiled xe2x80x9cMethod and Apparatus for Extending PBX Features via the Public Networkxe2x80x9d, discloses a system and method for allowing clients with a variety of teleworking devices, including digital and/or non-specialized dual-tone multi frequency (DTMF) telephones, to invoke PBX (private branch exchange) features. The user can invoke all or, alternatively, major PBX functions from any location.
In a preferred embodiment of the application referenced in the previous paragraph, a mobility circuit board system (IGate, SMPLX, WAML) includes a set of ports, called (herein) fictitious ports, that are not dedicated to fixed branch extensions. A fictitious port on a mobility board is assigned to a teleworker. The circuit board is responsible for enabling a teleworker at a remote phone to be treated by the switch as if he were connected to a standard physical port of the switch. When a teleworker logs in, he is assigned a fictitious port, which supports access to PBX functions.
After logging in, the teleworker can input digits to access PBX features (via feature code) or digits to call an inside or outside party via routing through the PBX. The digits are sent to the teleworking server (TW server, TWS). If a feature code is recognized by the server, the digits are suppressed from reaching the other party, and the teleworking server invokes the requested feature and sends the proper signals to the switch. The system thus provides the teleworker PBX functions at any location. In alternatives, an interactive voice recognition (IVR) system with prompts can be used to signal selection of PBX features.
Among other features, the system and method also provide for identification and call-back to avoid toll charges; activation and deactivation of call redirection; entering new call redirection destinations; identification of call redirection phone numbers; receiving and making both business and personal calls; activation and deactivation of voicemail and fax mail notifications; locating the teleworker; and dialing into specific numbers that activate and/or deactivate teleworking features without requiring user input and without requiring the call to be answered.
A method 300 for logging in is illustrated in FIG. 4. At step 302, the teleworking client calls the system. (In alternatives, the system places a call to the teleworking client.) At step 304, the teleworking client logs in, including an optional sub-step 306, at which the calling line is identified, and an optional sub-step 308, at which the teleworking client enters a PIN. Neither step, either step, or both steps can be implemented as part of login. Furthermore, other identifiers such as voice recognition can be added or used as alternatives.
At step 310, the teleworking server (TWS) checks the login. If,the login is not approved, the method loops back to step 304. As indicated by optional step 312, the number of attempts can be regulated by an attempt counter or a timeout timer. If the process times out, the method ends, at a step 314.
If the login is approved, the method continues to step 316, and the IGate assigns a fictitious port to the user. At a step 318, the TWS assigns the teleworking client""s office extension to the fictitious port. An optional step 320 makes a subset of PBX features available to the fictitious port; alternatively, the full set of features is available. At a step 322, the PBX features can be accessed at the teleworking client""s remote site, the site from which the original call was placed.
One unusual problem arises when a teleworking client is coupled to a remote PBX/MLTS (multiline telephone system) and the teleworking client calls an emergency telephone number. In the U.S., the number 911 is designated as an emergency number through which police, fire, and medical emergencies may be reported.
Normally, when a caller dials 911, the call is directed to a public safety answering point (PSAP) with a Caller ID (i.e., a subscriber line e.g., analog, BRI or Calling Party Number (CPN/ANI) (i.e., PRI or CAMA trunk). When the Caller ID is on a device behind a PBX/MLTS, an emergency location identification number (ELIN as defined by the National Emergency Number Association), in addition to the caller ID, is currently required by some legislative bodies to be transmitted from the caller""s PBX/MLTS to the central office and the PSAP. The ELIN represents (i.e., indicates a 10-digit NANP number) the location of the caller, e.g. street address.
When a teleworking client calls 911, the call is handled by the PBX/MLTS as if the caller were located at the same location as the PBX/MLTS. Thus, incorrect ELIN and caller ID information are transmitted to the PSAP. Moreover, the call may not even be directed to the correct PSAP as the teleworking client and the PBX/MLTS may be located in different PSAP jurisdictions e.g., cities or even different states.
It is therefore an object of the invention to provide methods and apparatus for dialing an emergency telephone number from a teleworking client.
It is also an object of the invention to provide methods and apparatus for intercepting xe2x80x9cemergencyxe2x80x9d digits dialed by the teleworking client, uncoupling the teleworking client from the PBX/MLTS, coupling the teleworking client to the PSTN, and transmitting the emergency digits over the PSTN.
It is another object of the invention to provide methods and apparatus for maintaining a database of emergency numbers to be intercepted.
In accord with these objects which will be discussed in detail below, the methods according to the invention include detecting at the teleworking client when an emergency number is dialed, disconnecting the teleworking client from the PBX/MLTS, connecting the teleworking client to the PSTN, and dialing a stored number associated with that number which was dialed. The apparatus of the invention resides in software that is installed in off the shelf hardware. Though the invention is described with reference to a teleworking client, it may also be applied to any other dialup network connection. The emergency digits (dialed and subsequently signalled to the PSTN) are not limited to emergency numbers, but are determined by the TW client via administration.